Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-in-single-out, multiple-in-single-out, single-in-multiple-out (SIMO) or a multiple-in-multiple-out (MIMO) system.
Due to data traffic, channel characteristics, or mobility of user equipment (UE), a need frequently arises for a particular UE to be handed over (i.e., hand-down, hand-up, etc.) between different access nodes. This handover process is complicated by the various states that a UE can be in for battery savings or channel efficiency (e.g., idle, active, discontinuous reception/transmission). This handover process is also complicated by hand offs being made between different radio access technologies (RAT). Other approaches, to the extent that inter-system RAT is accommodated, are believed to be overly complicated (e.g., in Wideband Code Division Multiple Access (WCDMA)).